Where it's printed
The app reads exactly three characters for MAC, so the shape to look for is a short mark like A63. Where the mark sits varies by product; the batch code guide covers where to look.
How the code is built
The app reads MAC with the same rule as Estée Lauder. The first character is ignored, the second is the month and the third is the last digit of the year. Digits repeat every ten years, so a 3 here means 2023.
Worked example
A63. The 6 is June and the 3 is 2023, so this was made in June 2023. The app uses 36 months for MAC, which puts the best before date at June 2026. In November 2026 this one is already about 5 months past it.
The date would be the same on an Estée Lauder pack; the shelf life is what changes, 36 months here against 60 there. Check the date before you reach for an old favorite.
Variants and edge cases
The app handles the variants and edge cases for you. Some codes the rule can't date; the app says so instead of guessing.
Shelf life and the PAO symbol
The app uses 36 months for MAC. That figure doesn't come from a MAC page. It rests on a MAC makeup artist quoted in 2017 press saying unopened products last at least three years, so use it as a rough guide. Clinique, from the same group, says at least 30 months.
For anything you've opened, the PAO symbol is the number to follow, the open jar with a figure like 12M.
Cosmetic Checker is independent and isn’t affiliated with MAC.